System and method for tuning transformers

ABSTRACT

A system and method for tuning a transformer is provided. A transformer fixture may connect a switching network to a plurality of inductors of a transformer. At least one computing device may calculate a target number of turns for a primary coil and a secondary coil of the transformer based on a frequency response of the transformer. The switching network may connect the inductors of the transformer together in a pattern that results in the primary coil and secondary coil having the target number of turns.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional, which claims the benefit ofU.S. Non-Provisional application Ser. No. 14/675,541, titled SYSTEM ANDMETHOD FOR TUNING TRANSFORMERS, filed on Mar. 31, 2015, which alsoclaims the benefit of U.S. Provisional Application No. 61/972,701,titled SYSTEM AND METHOD FOR TUNING TRANSFORMERS, filed Mar. 31, 2014,the disclosure of which is expressly incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention described herein includes contributions by one or moreemployees of the Department of the Navy made in performance of officialduties and may be manufactured, used and licensed by or for the UnitedStates Government for any governmental purpose without payment of anyroyalties thereon. This invention (NC 103,111) is assigned to the UnitedStates Government and is available for licensing for commercialpurposes. Licensing and technical inquiries may be directed to theTechnology Transfer Office, Naval Surface Warfare Center Crane, email:Cran_CTO@navy.mil.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a system and method fortuning transformers, and more particularly to a system and method fortuning a transformer of a transducer such as a Tonpilz transducer.

BACKGROUND OF THE DISCLOSURE

A transformer includes a primary winding and a secondary winding eachcomprised of one or more inductors. In some systems, the number of turnsof the primary and secondary windings of the transformer may be adjustedto tune the transformer. A known method of tuning a transformer involvesa test technician using alligator clipped wires to manually connectinductors in the transformer together to vary the number of turns ofcorresponding windings. The test technician uses a trial and errorapproach by changing the connections of the clips and measuring theimpedance and frequency of the transformer until a target frequencyresponse is achieved. Manually connecting clips to adjust the number ofturns of the coils sometimes results in short circuits between the clipsand inductors. Further, such a trial and error approach to transformertuning is time consuming and inefficient. In some environments, theclips are manually connected to the inductors above eye level while thetest technician is sitting or below eye level while the test technicianis standing. This ergonomic difficulty results in discomfort to the testtechnician as more units are tested.

SUMMARY OF EMBODIMENTS OF THE DISCLOSURE

A transformer fixture is provided that connects a switching network totransformer inductors. An impedance analyzer performs a frequency sweepof the transformer. Computer logic controls the switching network toautomatically vary the connection pattern of the inductors to achieve aproper frequency and/or impedance response of the transformer.

In an exemplary embodiment of the present disclosure, a method fortuning a transformer is provided. The method includes affixing atransformer fixture to a transformer. The transformer includes aplurality of inductors and a plurality of terminals. The transformerfixture includes a plurality of electrical connectors configured to makeelectrical contact with the plurality of inductors during the affixing.The method includes providing a switching network, and the switchingnetwork includes a plurality of switches coupled to the plurality ofelectrical connectors of the transformer fixture. The switching networkis operative to connect at least one first inductor of the plurality ofinductors to a first terminal of the transformer to form a primary coilof the transformer. The switching network is operative to connect atleast one second inductor of the plurality of inductors to a secondterminal of the transformer to form a secondary coil of the transformer.The method further includes providing an impedance analyzer inelectrical communication with the transformer. The impedance analyzer isoperative to execute a frequency sweep of the transformer and todetermine a frequency response of the transformer based on the frequencysweep. The method further includes executing a computer program on atleast one computing device. The at least one computing device whenexecuting the computer program is operative to calculate a target numberof turns of at least one of the primary coil and the secondary coil ofthe transformer based on the frequency response of the transformer. Theat least one computing device is operative to control the switchingnetwork to adjust the plurality of switches to connect at least aportion of the plurality of inductors of the transformer to at least oneterminal of the transformer to configure the at least one of the primarycoil and the secondary coil with the target number of turns.

In another exemplary embodiment of the present disclosure, a method fortuning a transformer is provided. The method includes instructing, by atleast one computing device, an impedance analyzer to execute a frequencysweep of a transformer. The transformer includes a first coil and asecond coil. The method includes determining, by the at least onecomputing device, a frequency value corresponding to a maximum impedanceof the transformer observed during the frequency sweep. The methodincludes, in response to the frequency value being outside of athreshold frequency range, instructing, by the at least one computingdevice, a switching network coupled to the transformer to adjust anumber of turns of the first coil of the transformer. The switchingnetwork is coupled to a fixture coupled to the transformer. The methodincludes determining, by the at least one computing device, an impedancevalue of the transformer corresponding to a predetermined frequency. Themethod includes, in response to the impedance value being outside of athreshold impedance range, instructing, by the at least one computingdevice, the switching network to adjust a number of turns of the secondcoil of the transformer.

In yet another exemplary embodiment of the present disclosure, atransformer tuning system is provided. The system includes a fixtureremovably coupled to a transformer. The fixture includes a plurality ofelectrical connectors configured to engage a plurality of inductors ofthe transformer when the fixture is coupled to the transformer. Thesystem includes an impedance analyzer in communication with thetransformer. The impedance analyzer is operative to execute a frequencysweep of the transformer and to monitor a frequency response of thetransformer based on the frequency sweep. The system further includes aswitching network coupled to the fixture and including a plurality ofelectrical switches in electrical communication with the plurality ofelectrical connectors of the fixture. The switching network is operativeto selectively open and close the plurality of electrical switches toselectively connect at least one inductor of the plurality of inductorsof the transformer to at least one terminal of the transformer. Thesystem further includes at least one computing device in communicationwith the impedance analyzer and the switching network. The at least onecomputing device is operative to determine at least one of a frequencyvalue and an impedance value of the transformer following the frequencysweep. The frequency value corresponds to a maximum impedance of thetransformer observed during the frequency sweep, and the impedance valuecorresponds to a predetermined frequency applied to the transformer. Theat least one computing device is further operative to instruct theswitching network to adjust a number of turns of at least one of a firstcoil and a second coil of the transformer based on the at least one ofthe frequency value and the impedance value of the transformer.

In still another exemplary embodiment of the present disclosure, anon-transitory computer-readable medium includes executable instructionssuch that when executed by at least one processor cause the at least oneprocessor to instruct an impedance analyzer to execute a frequency sweepof a transformer, determine a frequency value corresponding to a maximumimpedance of the transformer observed during the frequency sweep,instruct a switching network coupled to the transformer to adjust anumber of turns of a first coil of the transformer in response to thefrequency value being outside of a threshold frequency range, determinean impedance value of the transformer corresponding to a predeterminedfrequency, and instruct the switching network to adjust a number ofturns of a second coil of the transformer in response to the impedancevalue being outside of a threshold impedance range.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be more readily understood in view of the followingdescription when accompanied by the below figures and wherein likereference numerals represent like elements:

FIG. 1 illustrates a block diagram of a system for tuning a transformerin accordance with an exemplary embodiment of the present disclosure;

FIG. 2 illustrates a diagram of a plurality of terminals and a pluralityof inductors of the transformer of FIG. 1 according to an exemplaryembodiment of the present disclosure;

FIG. 3 illustrates a schematic of a tuning test circuit including atransformer and a signal generator in accordance with an exemplaryembodiment of the present disclosure;

FIG. 4 illustrates a perspective view of a transformer fixture accordingto an exemplary embodiment of the present disclosure;

FIG. 5 illustrates a side perspective view of the transformer fixture ofFIG. 4 in accordance with an exemplary embodiment of the presentdisclosure;

FIG. 6 illustrates a diagram of a switching network matrix in accordancewith an exemplary embodiment of the present disclosure;

FIG. 7 illustrates a transformer tuning method according to an exemplaryembodiment of the present disclosure;

FIG. 8 illustrates a method for calculating a new number of turns on aprimary coil of a transformer in accordance with an illustrativeembodiment of the present disclosure;

FIG. 9 illustrates a method for calculating a new number of turns on asecondary coil of a transformer according to an illustrative embodimentof the present disclosure;

FIG. 10 illustrates a graphical user interface provided by a computingdevice of the transformer tuning system of FIG. 1 according to anillustrative embodiment of the present disclosure, the graphical userinterface displaying a test tab;

FIG. 11 illustrates the graphical user interface of FIG. 10 displayingan engineering data tab according to an illustrative embodiment of thepresent disclosure; and

FIG. 12 illustrates an exemplary method of operation by transformertuning logic of the computing device of FIG. 1 for performing atransformer tuning procedure.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring initially to FIG. 1, a system 100 for testing and tuning atransformer according to an exemplary embodiment is illustrated. System100 includes a computing device 102, a switching network 104, animpedance analyzer 106, and a transformer 110. Transformer 110 includesat least one primary coil 112 and at least one secondary coil 114 eachincluding a plurality of inductors. As described herein, the number ofturns of each coil 112, 114 is adjustable with switching network 104 byadjusting the connection pattern of the inductors of each coil 112, 114,as described herein. System 100 may be used to tune any suitabletransformer to a desired impedance and frequency response. In theillustrated embodiment, transformer 110 is a component of a transducer108, illustratively a Tonpilz transducer 108. System 100 may also beused to tune a transformer that is not a part of a transducer 108.

Computing device 102 is in communication with switching network 104 andimpedance analyzer 106 via respective communication wires or cables 150,152. Impedance analyzer 106 is in electrical communication withtransducer 108 via a communication cable or wires 148. In theillustrated embodiment, switching network 104 is supported by a fixture140 that mounts to transformer 110, and switching network 104 is inelectrical communication with transformer 110 via one or more connectors146, as described herein with respect to FIGS. 4 and 5. Computing device102 includes a display 118, one or more processors 120, and memory 122containing instructions such that when executed by the one or moreprocessors 120 causes the processor(s) 120 to perform the functionsdescribed herein. Processor(s) 120 illustratively includes transformertuning logic 124 operative to initiate, manage, and monitor thetransformer tuning procedure described herein. In the illustratedembodiment, computing device 102 is a laptop or a desktop computer orany other suitable computing device or system.

In one embodiment, impedance analyzer 106 is a computing device orcomputing apparatus externally coupled to computing device 102 viacommunication cables 152. Impedance analyzer 106 includes at least oneprocessor 130 that executes instructions stored in internal or externalmemory 132 for performing the impedance analyzer functionality describedherein. Impedance analyzer 106 includes a signal generator 136controlled by processor 130 for generating a voltage or current signalprovided to transducer 108 at various frequencies during execution ofthe frequency sweep of transformer 110. Impedance analyzer 106 furtherincludes a display 134 for displaying feedback and status information toa user. In one embodiment, impedance analyzer 106 is an Agilent® RFNetwork/Spectrum/Impedance Analyzer provided by Agilent Technologies,Inc. headquartered in Santa Clara, Calif., although another suitableimpedance analyzer may be provided. In another embodiment, impedanceanalyzer 106 includes logic contained internal to computing device 102.

In the illustrated embodiment, primary and secondary coils 112 and 114of transformer 110 are formed based on the connection pattern of theplurality of inductors of coils 112 and 114. The inductors of each coil112, 114 have different numbers of turns. Depending on the connectionpattern of the inductors, the number of turns on each coil 112, 114 maybe varied via switching network 104. Switching network 104 controls theconnection pattern by selectively closing and opening electronicswitches 144 that connect particular inductors based on commands fromcomputing device 102, as described herein.

Computing device 102 executes a computer program stored in memory 122 torun the transformer tuning procedure. In an exemplary operation of thetuning procedure, computing device 102 directs impedance analyzer 106 toperform a frequency sweep on transformer 110, such as a sweep frequencyresponse analysis (SFRA) of transformer 110. The frequency sweepincludes impedance analyzer 106 generating a test signal with signalgenerator 136 at a range of frequencies and providing the signal totransformer 110 across the frequency range while monitoring the inputimpedance of transformer 110 at each frequency. In one embodiment, thesignal is a low voltage signal, such as a 1 volt signal, for example.Impedance analyzer 106 collects and stores data representing theresulting frequency response of transformer 110 including the testedfrequency values and corresponding impedance values.

Computing device 102 obtains from impedance analyzer 106 the resultingimpedance values of transformer 110 as a function of frequency.Computing device 102 analyzes the data and determines the frequency atwhich the observed maximum impedance of transformer 110 is achieved. Ifthis frequency value is not approximately equal to a predetermineddesired frequency value (or within a predetermined frequency range),then computing device 102 instructs switching network 104 to adjust thenumber of turns on primary coil 112. In particular, computing device 102calculates a new target number of turns for primary coil 112 (see FIG.8) based on the detected frequency value and the desired frequency valueor range. Computing device 102 then determines which inductors should beconnected to achieve the target number of turns. Computing device 102communicates commands and/or connection pattern data to switchingnetwork 104 identifying which inductors of transformer 110 to connecttogether, and switching network 104 closes and opens appropriateswitches 144 to achieve the connection pattern that results in thetarget new number of turns on primary coil 112.

In one embodiment, computing device 102 instructs impedance analyzer 106to provide the test signal again to transformer 110 having the newconnection pattern of primary coil 112. The test signal is applied atleast at a predetermined frequency value, and in some embodiments thetest signal may be applied across the full range of frequencies of thefrequency sweep. Based on the results from impedance analyzer 106,computing device 102 determines the impedance of transformer 110 thatresults when the signal is applied at the predetermined frequency value.In one embodiment, the predetermined frequency value used following theprimary coil adjustment is the same as the predetermined frequency valueused to determine the maximum impedance value prior to the primary coiladjustment. In one embodiment, the predetermined frequency is 3kilohertz (kHz) although any suitable predetermined frequency may beused. If the impedance of transformer 110 at the predetermined frequencyfalls outside a predetermined desired impedance range, then the numberof turns on secondary coil 114 is adjusted. In one embodiment, thedesired impedance range for the predetermined frequency is 62-70 ohms,although any suitable target impedance value or range may be used.Computing device 102 calculates a new target number of turns forsecondary coil 114 based on the measured impedance and the desiredimpedance for that frequency (see FIG. 9). Computing device 102 thendetermines which inductors should be connected to achieve the targetnumber of turns. Computing device 102 communicates commands and/orconnection pattern data to switching network 104, and switching network104 closes and opens the appropriate switches to achieve the connectionpattern that results in the target number of turns on secondary coil114.

In one embodiment, switching network 104 of FIG. 1 includes a pluralityof removable switching cards 142 each including a plurality of switches144. In one embodiment, each card 142 includes a circuit board and aplurality of electrical switches mounted to the circuit board. In theillustrated embodiment, the circuit boards of cards 142 are wiredaccording to the switching matrix 600 of FIG. 6, as described herein.The switching cards 142 are coupled to fixture 140 to provide theswitching network 104. In one embodiment, computing device 102 controlsswitching network 104 to selectively open or close each switch 144 bycommunicating data or control signals to switching network 104.Exemplary cards 142 include Model 7052 4X5 Matrix Switch Cards providedby Keithley Instruments, Inc. headquartered in Solon, Ohio, althoughother suitable switching cards 142 may be provided. In one embodiment,switches 144 include 3-pole Form A contacts.

Referring to FIG. 2, an exemplary diagram 200 of an inductor andterminal layout of transformer 110 of FIG. 1 is illustrated. Asillustrated with diagram 200, in one embodiment transformer 110 includesfour terminals 202 (labeled 1 through 4) and eleven inductors 204,although fewer or additional terminals and inductors may be used.Inductors 204 are connected to corresponding inductor terminals Athrough V. When fixture 140 of FIG. 1 is affixed to transformer 110,inductor terminals A through V and transformer terminals 202 areconnected to switches 144 of switching network 104 (FIG. 1). Primarycoil 112 and secondary coil 114 of transformer 110 (FIG. 1) are formedwhen switching network 104 selectively connects inductor terminalstogether to form a number of turns of each coil 112, 114. In theillustrated embodiment, transformer 110 of FIG. 1 is a step-uptransformer with primary coil 112 formed by one or more inductors 204 ofterminals A-J and secondary coil 114 formed by one or more inductors 204of terminals K-V. Other suitable transformer configurations may beprovided.

In the illustrated embodiment, a first inductor 206 is connected at oneend to a transformer terminal 202 (terminal 1) and at the other end toinductor terminal Q. Similarly, a second inductor 208 is connected atone end to another transformer terminal 202 (terminal 4) and at theother end to inductor terminal A. The exemplary number of turns of eachinductor 204 is shown below each inductor 204 in FIG. 2. In theillustrated embodiment, the inductor A-4 (inductor 208) includes 220.5turns, inductor B-F includes 5 turns, inductor C-G includes 10 turns,inductor D-H includes 18 turns, inductor E-J includes 22 turns, inductorK-R includes 8 turns, inductor L-S includes 10 turns, inductor M-Tincludes 21 turns, inductor N-U includes 32 turns, inductor P-V includes73 turns, and inductor 1-Q (inductor 206) includes 952.5 turns. Othersuitable configurations and numbers of inductors 204 may be provided.

In another embodiment, first inductor 206 and second inductor 208 arenot directly connected to transformer terminals 202, but rather areconnected to additional inductor terminals which are connected toswitches of switching network 104. In this embodiment, switching network104 provides electrical connections between terminals 202 and theswitches connected to inductors 206, 208. In one embodiment, computingdevice 102 provides diagram 200 for display on display 118 (FIG. 1).

Referring to FIG. 3, an exemplary schematic of a test circuit 300 isillustrated according to an embodiment. Test circuit 300 includes atransformer 320, such as transformer 110 of FIG. 1, including a primarycoil 316 and a secondary coil 318. Test circuit 300 further includes abridge rectifier 304 and a capacitor bank 306. In one embodiment,transformer 320, bridge rectifier 304, and capacitor bank 306 form atleast a portion of transducer 108 of FIG. 1. Transformer 320 includes afirst transformer terminal 308, a second transformer terminal 310, athird transformer terminal 312, a fourth transformer terminal 314corresponding to respective terminals 1 through 4 of FIG. 2. Testcircuit 300 further includes a power source or signal generator 302coupled to the transformer 320 for providing the test signal of thefrequency sweep. In one embodiment, signal generator 302 is provided byimpedance analyzer 106 of FIG. 1 for executing the frequency sweep oftransducer 108. In the illustrated embodiment, signal generator 302provides a 600 volt, 3 kHz alternating current (AC) signal. In oneembodiment, impedance analyzer 106 records the overall impedance ofcircuit 300 at the frequencies of the frequency sweep. In oneembodiment, capacitor bank 306 includes multiple ceramic rings inparallel that hold a voltage potential and are operative to release thevoltage potential for sending sound pressure signals and to provideelectrical input based on received sound pressure signals.

Signal generator 302 is connected to second transformer terminal 310,while first transformer terminal 308 is connected to one side ofcapacitor bank 306 and fourth transformer terminal 314 is connected toone side of bridge rectifier 304. Third transformer terminal 312connects to ground, the other side of bridge rectifier 304, and theother side of capacitor bank 306. In one embodiment, bridge rectifier304 allows for sending and receiving sound signals by allowing currentto flow into and out of transformer 320.

An exemplary transformer fixture 140 of FIG. 1 is illustrated in FIGS. 4and 5 with transformer fixture 400. Transformer fixture 400 mounts totransformer 110 and supports switching network 104 of FIG. 1.Transformer fixture 400 includes a frame 404 and a plurality ofconnectors or terminals 402 (FIG. 4). In the illustrated embodiment,connectors 402 include springed pins, such as waffle probes, that arearranged to make electrical contact with corresponding transformerterminals 202 and inductor terminals of transformer 110 (FIG. 2) whenfixture 400 is mounted to transformer 110. Connectors 402 may includeother connector types suitable for engaging terminals of transformer110. Connectors 402 labeled A through V are configured to engagecorresponding inductor terminals labeled A through V (FIG. 2), andconnectors 402 labeled 1 through 4 are configured to engagecorresponding transformer terminals 202 labeled 1 through 4 (FIG. 2).When fixture 400 is mounted to transformer 110, the springed connectors402 are compressed by the force of corresponding terminals oftransformer 110 to provide an electrical connection therebetween.

Frame 404 of fixture 400 includes a plurality of clamp portions 410spaced around the perimeter of frame 404. In the illustrated embodiment,four clamp portions 410 are provided, with one at each corner of fixture400. Clamp portions 410 include flanged ends that engage a correspondingframe 430 (FIG. 5) of transformer 110 for mounting fixture 400 to frame430. In one embodiment, clamp portions 410 are adapted to flex outwardlyand snap onto transformer frame 430 when pushed onto frame 430.Fasteners 406 are tightened to clamp fixture 400 onto transformer frame430. In one embodiment, frame 404 of fixture 400 is made of plastic oranother suitable polymer or nonconductive material. Connectors 402 areillustratively coupled to a nonconductive internal cover 414 that isseated in an interior region formed by a perimeter wall 416 of frame404. In the illustrated embodiment, wall 416 has a height suitable forbiasing connectors 402 at a sufficient distance from transformer 110such that connectors 402 compress when fixture 400 is mounted totransformer 110.

As illustrated in FIG. 5, fixture 400 includes an outer cover 420coupled to frame 404 via fasteners 422. Cover 420, which may be plasticor another suitable nonconductive material, includes an opening forrouting communication wires or cables 434 from computing device 102 toswitching network 104 (FIG. 1) positioned in the interior of fixture400. Wires 434, which may include wires 148, 152 of FIG. 1, routecontrol, data, and feedback signals between computing device 102 andimpedance analyzer 106 and the switching network 104. Cover 420 isremovable to access cards 142 (FIG. 1) of switching network 104. Groundwires 436 are illustratively routed from terminals 202 (FIG. 2) oftransformer 110 and coupled to ground. A wire connector 440 connectswire bundle 434 to switching network 104 inside fixture 400. In oneembodiment, connector 440 includes a general purpose interface bus(GPIB) connector for coupling to switching network 104, although othersuitable connectors may be used. Connector 440 may include anothersuitable type of electrical connector with multiple pins, including aD-sub or USB connector, for example.

Referring to FIG. 6, a diagram of an exemplary switching matrix 600 fora switching network 104 (FIG. 1) is illustrated. Data representingswitching matrix 600 is stored in memory 122 of computing device 102.Switching matrix 600 illustratively identifies six switching cards 142in column 602, although any suitable number of cards 142 may be providedin switching network 104. Matrix 600 represents each switching card 142with four rows 604 and ten columns 606, wherein each position (row X,column Y) in the matrix 600 represents a corresponding switch 144(FIG. 1) of the corresponding card 142.

As described above, with switching cards 142 of FIG. 1 inserted intofixture 140, switching matrix 600 identifies which terminals oftransformer 110 the switches 144 connect to. Computing device 102connected to switching network 104 opens or closes each switch 144 bycommunicating data to switching network 104 that represents a cardnumber, row number, and column number. For example, to connect inductorterminal B of transformer 110 to inductor terminal D, computing device102 instructs switching network 104 to close the switch 144 indicated bycard 1, row 2, column 3 of matrix 600. As another example, to connectinductor terminal K to inductor terminal Q, computing device 102instructs switching network 104 to actuate the switch 144 indicated bycard 4, row 2, column 1, thereby adding eight turns to secondary coil114 (see FIG. 2). In one embodiment, switching network 104 includes 80switches 144 to provide the connections designated in switching matrix600, although another suitable number of switches 144 may be provided.In one embodiment, card 6 identified in column 602 of matrix 600 isoperative to connect impedance analyzer 106 (FIG. 1) directly toswitching network 104 and transformer 110 via a cable connector suchthat computing device 110 is able to switch connection to transformer110 on and off.

FIGS. 7-9 illustrate an exemplary method of operation of system 100 ofFIG. 1. Reference is made to FIGS. 1-5 throughout the followingdescription of FIGS. 7-9.

Referring to FIG. 7, a transformer tuning method 700 according to anexemplary embodiment is illustrated. At block 702, transformer tuningmethod 700 is started. For example, after installing fixture 400 (FIG.4) on transformer 110 and connecting the appropriate cables to switchingnetwork 104 and impedance analyzer 106, a user initiates the tuningprocedure by providing a start input to computing device 102 (e.g.,selecting input 1004 of FIG. 10). At block 704, an initial connectionpattern for the inductors of transformer 110 is selected by computingdevice 102 and implemented via switching network 104. In one embodiment,a default connection pattern is provided by computing device 102 basedon an identified type or model of transformer 110. In anotherembodiment, a user selects the initial connection pattern through a userinterface (e.g., user interface 1000 of FIG. 11) prior to starting thetuning procedure. When the initial connection pattern is selected,computing device 102 instructs switching network 104 to adjust theswitches 144 according to the pattern to thereby create primary andsecondary coils 112, 114 of transformer 110 each having the desirednumber of turns identified with the initial connection pattern.

At block 706, computing device 102 instructs impedance analyzer 106 toperform a frequency sweep of transformer 110 configured with the initialconnection pattern. The frequency response data is provided to orretrieved by computing device 102. Based on the data, computing device102 determines the frequency F₁ (F_(n) for nth iteration) at whichtransformer 110 has a maximum input impedance Z_(M).

At block 707, the frequency F₁ at which transformer 110 has a maximuminput impedance Z_(M) is compared to a desired predetermined frequencyvalue or frequency range F_(D) stored at computing device 102. In thepresent embodiment, the desired predetermined frequency F_(D) is 3 kHz,although other suitable frequencies may be used. If the frequency F isapproximately equal to the desired frequency F_(D) (i.e., within thedesired range) at block 707, the procedure proceeds to block 710described below. If the frequency F₁ is not approximately equal to thedesired frequency F_(D) (i.e., not within the desired range) at block707, computing device 102 adjusts the frequency response of transformer110 at block 708 by controlling switching network 104 to change thenumber of turns (and thereby inductance) on primary coil 112. Inparticular, computing device 102 calculates a new number of turns atblock 708 (see FIG. 8) and instructs switching network 104 to connectselect inductors together to achieve the desired number of turns, asdescribed herein. The resulting connection pattern is stored in memory122 of computing device 102.

At block 710, after reconfiguring the turns on primary coil 112,computing device 102 instructs impedance analyzer 106 to provide asignal to transformer 110 at the predetermined desired frequency F_(D)and to measure the transformer impedance Z₁ (Z_(n) for nth iteration) atthe desired frequency F_(D). In one embodiment, the predeterminedfrequency F_(D) is 3 kHz, although other suitable values may be used.The measured impedance value Z₁ is provided to or retrieved by computingdevice 102, and at block 712 computing device 102 compares the measuredimpedance value Z₁ to a predetermined desired impedance or impedancerange Z_(D). In one embodiment, the predetermined desired impedancerange is 62-70 ohms although other suitable values may be used. If themeasured impedance Z₁ is sufficiently close to the desired impedancevalue Z_(D) (i.e., within the desired range), the process finishes atblock 718 until another tuning procedure is initiated by the user.

If the measured impedance Z₁ is sufficiently close to the desiredimpedance value Z_(D) (i.e., not within the desired range), at block712, then the process advances to block 714. At block 714, the impedanceof transformer 110 is adjusted by changing a number of turns onsecondary coil 114. In particular, computing device 102 calculates a newnumber of turns (see FIG. 9) and instructs switching network 104 toconnect various inductors of secondary coil 114 together to achieve thedesired number of turns. The resulting connection pattern is stored inmemory 122 of computing device 102, and the process returns to block706. At block 706, impedance analyzer 106 again executes a frequencysweep and measures the frequency response of transformer 110 configuredwith the new connection pattern, and computing device 102 determines thefrequency F₂ at which transformer 110 has a maximum input impedanceZ_(M). If the new determined frequency F₂ is sufficiently close to thedesired frequency F_(D) at block 707, then the process advances to block710 to measure the impedance Z₂ at the desired frequency F_(D). If themeasured impedance Z₂ is sufficiently close to the desired impedanceZ_(D) at block 712, the process has successfully tuned transformer 110and advances to block 718 where the process finishes. If the measuredimpedance Z₂ is not sufficiently close to the desired impedance Z_(D) atblock 712, then the method proceeds to block 714 to perform anotheriteration of the method. The tuning method performs n iterations untilcomputing device 102 determines transformer 110 is tuned properly basedon the frequency F_(n) and the measured impedance Z_(n) being within therespective ranges at blocks 707 and 712.

In one embodiment, computing device 102 instructs the user via userinterface 1000 (FIG. 10) that the tuning procedure is complete andidentifies the resulting connection pattern. In one embodiment, the userthen removes the transformer fixture 140 (FIG. 1) from transformer 110and configures the inductors of transformer 110 according to theresulting connection pattern provided with computing device 102. Forexample, the user hardwires and/or solders the inductors of each coil112, 114 of transformer 110 according to the resulting connectionpattern.

Referring to FIG. 8, an exemplary method 800 for calculating a newnumber of turns on primary coil 112 of transformer 110 (block 708 ofFIG. 7) is illustrated. At block 802, computing device 102 subtracts thetarget frequency F_(D) from the actual frequency F_(n). At block 804,computing device 102 multiplies the difference from block 802 by amultiplier, illustratively a fraction. In the present embodiment, themultiplier is 0.75, although other suitable multipliers may be providedbased on the desired amount of adjustment each iteration. At block 806,computing device 102 adds the current total number of turns oftransformer 110 (primary and secondary coils 112, 114) to the result ofblock 804. At block 808, computing device 102 compares the currentlyused inductor connection pattern to the connection patterns that werepreviously used and stored in computing device 102 during the currenttuning procedure (see FIG. 7). If the current connection pattern has notbeen previously used at block 808, the method proceeds to block 812. Ifthe current connection pattern has been previously used, then computingdevice 102 proceeds to block 810 to add an incremental number of turnsto primary coil 112. In one embodiment, eight turns are added to theresult of block 806, although other suitable increments may be useddepending on available inductors of primary coil 112 and the size ofprimary coil 112. At block 812, computing device 102 subtracts thenumber of“below” turns, or the turns on the primary coil 112, from theresult of block 810 (or block 808 if block 810 is skipped). The resultof block 812 is the new number of turns on primary coil 112 implementedat block 708 of FIG. 7. Other suitable methods for determining theadjustment to the number of primary coil turns may be provided.

In some embodiments, the multiplier in block 804 may be adjusted. Alarger multiplier results in a larger change to the number of turns eachiteration while a smaller multiplier results in a more gradual change tothe number of turns each iteration. In one embodiment, the number ofturns incremented at block 810 is set to the number of turns of thesmallest available inductor of primary coil 112. In one embodiment, thenumber of turns incremented at block 810 is set to a larger number incircuits where eight turns results in an insignificant change in primarycoil inductance. Similarly, the number of turns incremented at block 810is set to a smaller number in circuits where eight turns results in toosignificant of a change in primary coil inductance. In an alternativeembodiment, the turns increment in block 810 may be subtracted ratherthan added.

Referring to FIG. 9, an exemplary method 900 for calculating a newnumber of turns on secondary coil 114 of transformer 110 (block 714 ofFIG. 7) is illustrated. At block 902, computing device 102 subtracts themeasured impedance Z_(n) from the target impedance Z_(D). At block 904,computing device 102 optionally multiplies the result of block 902 by amultiplier. In the illustrated embodiment, the multiplier is one,although other suitable multipliers may be used based on the desiredamount of adjustment each iteration. At block 906, computing device 102adds the total number of turns of transformer 110 (primary and secondarycoils 112, 114) currently being used to the result of block 904. Atblock 908, computing device 102 compares the currently used connectionpattern to the connection patterns that were previously used and storedin computing device 102 during the current tuning procedure (see FIG.7). If the connection pattern has not been previously used at block 908,the method proceeds to block 912. If the current connection pattern hasbeen previously used, then computing device 102 proceeds to block 910 toadd an incremental number of turns to secondary coil 114. In oneembodiment, five turns are added to the result of block 906, althoughother suitable increments may be used depending on available inductorsof secondary coil 114 and the size of secondary coil 114. At block 912,computing device 102 subtracts the number of “above” turns, or the turnscurrently on secondary coil 112, from the result of block 910 (or block908 if 910 is skipped). The result of block 912 is the new number ofturns on secondary coil 114 implemented at block 714 of FIG. 7. Othersuitable methods for determining the adjustment to the number ofsecondary coil turns may be provided.

In some embodiments, the multiplier in block 904 may be adjusted. Alarger multiplier results in a larger change to the number of turns eachiteration while a smaller multiplier results in a more gradual change tothe number of turns each iteration. In one embodiment, the number ofturns incremented at block 910 is set to the number of turns of thesmallest available inductor of secondary coil 114. In one embodiment,the number of turns incremented at block 910 is set to a larger numberin circuits where five turns results in an insignificant change insecondary coil inductance. In one embodiment, the number of turnsincremented at block 810 is set to a smaller number in circuits wherefive turns results in too significant of a change in secondary coilinductance. In an alternative embodiment, the turns increment in block910 may be subtracted rather than added.

Referring to FIGS. 10 and 11, a testing graphical user interface (GUI)1000 of transformer tuning system 100 of FIG. 1 is illustrated accordingto some embodiments. In one embodiment, GUI 1000 is provided bycomputing device 102 on display 118 of FIG. 1. A user provides userinput to GUI 1000 via any suitable user input device coupled tocomputing device 102, such as a touchscreen, keyboard, pointing device(e.g., mouse), etc. In the illustrated embodiment, testing GUI 1000includes a test tab 1016 and an engineering data tab 1116.

GUI 1000 includes selectable data, such as selectable inputs, fields,modules, tabs, drop-down menus, boxes, and other suitable selectabledata, that are linked to and provide input to the components of system100 of FIG. 1. In one embodiment, the selectable data of GUI 1000 isrendered in a manner that allows it to be individually selectable. Forexample, the selectable data is selected by a user with a mouse pointer,by touching a touchscreen of the user interface, by pressing keys of akeyboard, or by any other suitable selection mechanism. GUI 1000 furtherdisplays monitored data, including status and other feedback data,provided from components of system 100 that is displayed with theselectable data.

Referring to FIG. 10, test tab 1016 illustratively includes a serialnumber input field 1002, a start button 1004, a testing pattern window1006, a frequency output 1008, an impedance output 1010, an exit button1012, and a running indicator 1014. Field 1002 allows a user to enterthe serial or identification number of the transformer 110 (ortransducer 108) to be tested. In one embodiment, the initial connectionpattern of coils 112, 114 identified at block 704 of FIG. 7 isdetermined by computing device 102 based on the serial number entered infield 1002. A user selects start input 1004 to initiate the tuningprocedure after fixture 400 is coupled to transformer 110, system cablesare connected, and components are powered on by the user. Statusindicator 1014 displays a color (e.g., green or red) corresponding towhether the tuning procedure is running, stopped, or completed.Selection of exit button 1012 allows a user to interrupt the tuningprocedure and/or to exit the program. Field 1008 displays the inputfrequency F_(n) (illustratively in Hertz) that results in the maximuminput impedance Z_(M) (block 706 of FIG. 7) following the tuningprocedure. Field 1010 displays the impedance Z_(n) (illustratively inohms) of transformer 110 at the predetermined desired frequency F_(D)(block 710 of FIG. 7) following completion of the tuning procedure.

Window 1006 displays a visualization of the connection pattern of theprimary and secondary coils 112, 114 that results from the tuningprocedure. As illustrated, the visualization shows which inductors ofFIG. 2 have been connected to each other to achieve the resultingfrequency and impedance values displayed in respective fields 1008 and1010. In one embodiment, window 1006 further displays the real-timecurrent connection pattern of transformer 110 provided with switchingnetwork 104 as the tuning procedure steps through each tested patternwhile searching for the connection pattern that passes the test.

Referring to FIG. 11, engineering data tab 1116 of GUI 1000 is selected.Engineering data tab 1116 includes a switching network connectorselection 1102, an impedance analyzer connector selection 1104, acounter output 1106, an output array 1108, a starting secondary array1110, a starting primary array 1112, and an exit button 1114.

Switching network connector selection 1102 allows a user to select whichpin or pins of a connector to use as output from computing device 102 toswitching network 104 for controlling switching network 104. In oneembodiment, switching network 104 is connected to computing device 102by a GPIB connector. Impedance analyzer connector selection 1104 allowsa user to select which pin or pins of a connector to use as input tocomputing device 102 from impedance analyzer 106. In one embodiment,impedance analyzer 106 is connected to computing device 102 by a GPIBconnector. For example, impedance analyzer connector selection 1104allows the user to select from a dropdown menu which pin of the GPIBconnector computing device 102 will use to receive data from impedanceanalyzer 106. For example, the pins identified with respectiveselections 1102, 1104 may be based on the model or type of switchingcards 142 of switching network 104 or impedance analyzer 106 (FIG. 1).

Counter 1106 of FIG. 11 displays the number of connection patterns thathave been tested while running the tuning procedure of FIG. 7. Outputarray 1108 displays a table version of the current connection patternbeing tested. The letters correspond to inductor terminals and thenumbers correspond to transformer terminals, as described herein withrespect to FIG. 2. Starting secondary array 1110 allows a user to setthe starting (initial) connection pattern for secondary coil 114, andstarting primary array 1112 allows a user to set the starting (initial)connection pattern for primary coil 112 (e.g., see block 704 of FIG. 7).When initiating the transformer tuning process, computing device 102communicates data to switching network 104 causing switching network 104to close the appropriate switches 144 corresponding to the initialconnection patterns identified in arrays 1110 and 1112. Exit button 1114allows a user to interrupt the testing process and/or exit the program.

FIG. 12 illustrates an exemplary method of operation performed bycomputing device 102, and in particular by transformer tuning logic 124(FIG. 1), for performing a tuning procedure for transformer 110.Reference is made to FIGS. 1-5 throughout the following description ofFIG. 12. At block 1202, tuning logic 124 instructs impedance analyzer106 to execute a frequency sweep of transformer 110. At block 1204,tuning logic 124 determines a frequency value corresponding to a maximumimpedance of transformer 110 observed during the frequency sweep. Atblock 1206, in response to the frequency value being outside of athreshold frequency range, tuning logic 124 instructs switching network104 coupled transformer 110 to adjust a number of turns of a first coil(e.g., primary coil 112) of transformer 110. At block 1208, tuning logic124 determines an impedance value of transformer 110 corresponding to apredetermined frequency (e.g., frequency F_(D)). In one embodiment, theimpedance value is determined following adjustment of the number ofturns of the first coil by switching network 104. At block 1210, inresponse to the impedance value being outside of a threshold impedancerange, tuning logic 124 instructs switching network 104 to adjust anumber of turns of a second coil (e.g., secondary coil 114) oftransformer 110.

In one embodiment, tuning logic 124 further instructs impedance analyzer106, following adjustment of the number of turns of the first coil byswitching network 104, to provide a test signal to transformer 110 atthe predetermined frequency and to monitor the impedance of transformer110 at the predetermined frequency. In one embodiment, tuning logic 124calculates a target number of turns of the first coil and determines aconnection pattern of a plurality of inductors of the first coil. Theconnection pattern identifies which inductors of the first coil toconnect to at least one terminal 202 (FIG. 2) of transformer 110 toachieve the target number of turns. In one embodiment, tuning logic 124determines, following a second frequency sweep by impedance analyzer106, a second impedance value of transformer 110 corresponding to thepredetermined frequency. Tuning logic 124 instructs switching network104 to adjust the number of turns on the second coil in response to thesecond impedance value being outside of the threshold impedance range.In one embodiment, tuning logic 124 instructs switching network 104 bycommunicating switch commands to switching network 104 based on theconnection pattern.

In one embodiment, prior to installing fixture 400 (FIG. 3) ontransformer 110 and performing the tuning procedure, inductors oftransformer 110 are decoupled from each other (e.g., wiring or solderingconnections removed) such that transformer 110 has the base inductorconfiguration illustrated in FIG. 2. In one embodiment, once theconnection pattern is determined by computing device 102 following thetuning procedure, a technician removes the fixture 400 (FIG. 4) andswitching network 104 (FIG. 1) from transformer 110 and hardwires and/orsolders the inductors of transformer 110 according to the connectionpattern. As such, the tuning system 100 may then be coupled to anothertransformer 110 for testing. In one embodiment, tuning system 100includes multiple fixtures, switching networks, and impedance analyzerscoupled to computing device 102 for testing and tuning multipletransformers 110 simultaneously or in series.

In one embodiment, transducer 108 of FIG. 1 is a Tonpilz transducer 108.Tonpilz transducer 108 is operative to send and receive signals fordetecting a distance to an object. In one embodiment, Tonpilz transducer108 is mounted near a hull of a ship and is configured to communicatesonar signals underwater to detect a distance to other objects in thewater. Tonpilz transducer 108 and transformer 110 of FIG. 1 may beimplemented in other suitable environments.

The term “logic” or “control logic” as used herein may include softwareand/or firmware executing on one or more programmable processors,application-specific integrated circuits (ASICs), field-programmablegate arrays (FPGAs), digital signal processors (DSPs), hardwired logic,or combinations thereof. Therefore, in accordance with the embodiments,various logic may be implemented in any appropriate fashion and wouldremain in accordance with the embodiments herein disclosed.

The disclosed operations set forth herein may be carried out by one ormore suitable processors that are in communication with non-transitorycomputer readable medium such as but not limited to CDROM, RAM, otherforms of ROM, hard drives, distributed memory, etc. The non-transitorycomputer readable medium stores executable instructions that whenexecuted by the one or more processors cause the one or more processorsto perform, for example, the operations of computing device 102 andimpedance analyzer 106 described herein and/or the methods as describedwith reference to FIGS. 7-9 and 12.

While the embodiments have been described as having preferred designs,the disclosed embodiments can be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the embodiments using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this disclosure pertains and which fallwithin the limits of the appended claims.

The invention claimed is:
 1. A transformer tuning system comprising: afixture removably coupled to a transformer, the fixture including aplurality of electrical connectors configured to engage a plurality ofinductors of the transformer when the fixture is coupled to thetransformer; an impedance analyzer in communication with thetransformer, the impedance analyzer being operative to execute afrequency sweep of the transformer and to monitor a frequency responseof the transformer based on the frequency sweep; a switching networkcoupled to the fixture and including a plurality of electrical switchesin electrical communication with the plurality of electrical connectorsof the fixture, the switching network being operative to selectivelyopen and close the plurality of electrical switches to selectivelyconnect at least one inductor of the plurality of inductors of thetransformer to at least one terminal of the transformer; and at leastone computing device in communication with the impedance analyzer andthe switching network, the at least one computing device being operativeto determine at least one of a frequency value and an impedance value ofthe transformer following the frequency sweep, the frequency valuecorresponding to a maximum impedance of the transformer observed duringthe frequency sweep, the impedance value corresponding to apredetermined frequency applied to the transformer, and instruct theswitching network to adjust a number of turns of at least one of a firstcoil and a second coil of the transformer based on the at least one ofthe frequency value and the impedance value of the transformer.
 2. Thesystem of claim 1, wherein the at least one computing device isoperative to calculate a target number of turns of the at least one ofthe first coil and the second coil of the transformer, and determine aconnection pattern of the plurality of inductors of the transformer thatidentifies which inductors to connect to the at least one terminal ofthe transformer to achieve the target number of turns.
 3. The system ofclaim 1, wherein the at least one computing device is operative todetermine the impedance value corresponding to the predeterminedfrequency in response to the number of turns of the at least one of thefirst coil and the second coil being adjusted by the switching network.4. The system of claim 1, wherein the switching network includes aplurality of cards removably coupled to the fixture, and the pluralityof cards include the plurality of electrical switches.
 5. Anon-transitory computer-readable medium comprising: executableinstructions such that when executed by at least one processor cause theat least one processor to: instruct an impedance analyzer to execute afrequency sweep of a transformer; determine a frequency valuecorresponding to a maximum impedance of the transformer observed duringthe frequency sweep; in response to the frequency value being outside ofa threshold frequency range, instruct a switching network coupled to thetransformer to adjust a number of turns of a first coil of thetransformer; determine an impedance value of the transformercorresponding to a predetermined frequency; and in response to theimpedance value being outside of a threshold impedance range, instructthe switching network to adjust a number of turns of a second coil ofthe transformer.
 6. The non-transitory computer-readable medium of claim5, wherein the impedance value is determined in response to the numberof turns of the first coil of the transformer being adjusted by theswitching network.